Help with my build?

AMD phenom II X4 + HD7850 or 
AMD FX-6100 + HD 7770

ill be using this system only for gaming

and the Gigabyte GA-78LMT-S2P is enough or if i got a better motherboard will it differ in the performance

and shal i get 4 gigs or 8 gigs ? (will it make diffrence in gaming ?)

Thanks in advance

phenom x4 and a 7850 is better and that motherboard is fine if you dont overclock and I would get 8gb of ram.

4gbs is still enough for gaming if you close your apps in the backround. If you have extra cash get more ram but if you don't, get 1 stick of 4 and upgrade in the future. Also, 6300 is a must and 7770 is good enough, the phenom II x4 will bottleneck cards in the future. But wait for the new amd cards to come out (~October) and pick one of those or get a crazy price drop around that time.

If your in america:

Amazing case

So now i have 2 people with the opposite opinion 
that helped alot LOL 

What's your budget?

its not a budget its either this or that because i know the weird prices in my country

Sorry, just my opinion

Good Luck i'll be in and out of here

8GB.  My old 4GB pc had RAM usage at almost 100% the whole time during gaming.  And that's with one program open: TF2